Valves and the like that are used to control fluids such as gases in aircraft and spacecraft are exposed to conditions that place demands upon them that are not present in normal environments in which the majority of valves operate. For instance, valves that are used in aircraft and spacecraft can be subjected to extreme temperature variations that in many cases would cause normal valves to cease to function or to cease to function properly. For instance, low temperatures coupled with humidity that can be found in many aircraft situations can result in the formation of ice that can cause a valve to directly or indirectly freeze up and fail to function.
Valves that are used in aircraft and spacecraft are also subjected to possible severe forces as the aircraft or spacecraft maneuvers or departs from the ground. This can result in the distortion of valve components and can produce malfunctioning of the valve or at least cause increased wear on components of the valve that will eventually cause the valve to fail. Also, many valves on aircraft and spacecraft are operated by fluids located on the aircraft or spacecraft and such fluids must be used sparingly in most cases. This means that the valve must be efficient in its use of the operating fluid.
Since safety is of extreme importance in aircraft and spacecraft, it is essential that the valve used on such craft be extremely reliable. Usually reliability is increased by making the valve simple in its operation with a minimum of parts that can fail.
The present control valve apparatus is used with a source of engine bleed air on an aircraft such as an airliner. In this use bleed air is used to operate a valve to control the amount of bleed air that is allowed to pass into the inlet portion of an air turbine that is located on the aircraft.
In the past, with such units shut-off and modulation was either accomplished with butterfly valves or complex variable inlet guide vanes. Unfortunately, butterfly valves are not entirely satisfactory. Butterfly valves result in severe flow distortion during throttling, with significantly greater noise levels. They also result in significantly greater pressure drop at low inlet pressures. Significant ice breaking capacity on a typical butterfly valve requires large actuators attached to the valve body with a corresponding large overhanging moment.
These problems are overcome with the present aircraft air control apparatus. For effective and safe use on aircraft the aircraft air control apparatus is compact and uses simple integration of a shut off valve and a modulating valve and has very high ice-breaking capacity allowing the valve to open and modulate after heavy ice build-up. The aircraft air control apparatus also has a low pressure drop through both the shut-off and modulating sections or elements of the assembly permitting air drive unit operation at low bleed air pressure and it also has low noise at extreme throttling conditions.
This invention relates to air flow control and more particularly to air flow control on aircraft.
Accordingly, it is an object of the invention to provide an aircraft air control valve apparatus.
It is an object of the invention to provide an aircraft air control valve apparatus having a plurality of functions.
It is an object of the invention to provide an aircraft air control valve apparatus with both modulating and shut off functions.
It is an object of the invention to provide an aircraft air control valve apparatus that compactly incorporates both modulating and shut off functions in one valve unit.
It is an object of the invention to provide an aircraft air control valve apparatus that readily operates with available aircraft engine bleed air.
It is an object of the invention to provide an aircraft air control valve apparatus that allows both modulating and shut off functions after heavy ice build up on the aircraft air control valve apparatus.
It is an object of the invention to provide an aircraft air control valve apparatus having low pressure drop associated with both the modulating and shut off functions.
It is an object of the invention to provide an aircraft air control valve apparatus that has low noise.
It is an object of the invention to provide an aircraft air control valve apparatus that has low noise at extreme throttling conditions.
It is an object of the invention to provide an aircraft air control valve apparatus that is simple in its design.
It is an object of the invention to provide an aircraft air control valve apparatus that is simple in its operation.
It is an object of the invention to provide an aircraft air control valve apparatus that has similar parts.
It is an object of the invention to provide an aircraft air control valve apparatus that has parts that serve multiple functions.
It is an object of the invention to provide an aircraft air control valve apparatus that uses a common housing for multiple functions.
It is an object of the invention to provide an aircraft air control valve apparatus that uses a common shaft for multiple functions.
It is an object of the invention to provide an aircraft air control valve apparatus that is reliable in its operation.
It is an object of the invention to provide an aircraft air control valve apparatus that is easy to manufacture.
It is an object of the invention to provide an aircraft air control valve apparatus that is easy to service.
It is an object of the invention to provide an aircraft air control valve apparatus that is easy to repair.
It is an object of the invention to provide an aircraft air control valve apparatus that replaces existing less desirable butterfly valves.
It is an object of the invention to provide fluid control valve apparatus with multiple applications.
These and other objects of the invention will be apparent from the following described aircraft fluid control valve apparatus invention that has a hollow housing having two end portions and valve apparatus located at both end portions of the housing. A shut-off valve is located in one end portion of the hollow housing for starting and stopping the flow of fluid through said hollow housing and a modulating valve is located in the other end portion of the hollow housing for modulating the flow of fluid through the hollow housing.